ElasticSearch: formula cleanup
ElasticSearch: formula cleanup

This commit introduces couple of breaking, but important changes for
ElasticSearch:

1. The cluster is given a reasonably unique, though human-friendly name,
   based on the current user login name (`ENV['USER']`).  This minimizes
   conflicts and dubious [MasterNotDiscoveredException] errors when running
   a development cluster eg. within an office, on multiple workstations,
   with open firewalls.

2. This means the _path to data has changed_ and users will have to move
   it manually to new location. It should be safe to do so, while ES is not
   running.

3. The log files location also changed to a more appropriate one.

4. Standard error and ouput streams were redirected to /dev/null within
   the `plist` definition, since ES provides enough logging already.

The changes should be forward compatible with the complete rewrite of ES
config file in <https://github.com/elasticsearch/elasticsearch/blob/master/config/elasticsearch.yml>.

Closes Homebrew/homebrew#7946.

Signed-off-by: Jack Nagel <43386ce32af96f5c56f2a88e458cb94cebee3751@gmail.com>

edporras/homebrew-core,lembacon/homebrew-core,gserra-olx/homebrew-core,passerbyid/homebrew-core,moderndeveloperllc/homebrew-core,Linuxbrew/homebrew-core,dsXLII/homebrew-core,mvbattista/homebrew-core,reelsense/homebrew-core,ilovezfs/homebrew-core,bcg62/homebrew-core,filcab/homebrew-core,battlemidget/homebrew-core,bcg62/homebrew-core,forevergenin/homebrew-core,mfikes/homebrew-core,Homebrew/homebrew-core,phusion/homebrew-core,BrewTestBot/homebrew-core,phusion/homebrew-core,bigbes/homebrew-core,bfontaine/homebrew-core,DomT4/homebrew-core,jdubois/homebrew-core,zyedidia/homebrew-core,mahori/homebrew-core,LinuxbrewTestBot/homebrew-core,jvillard/homebrew-core,BrewTestBot/homebrew-core,wolffaxn/homebrew-core,stgraber/homebrew-core,uyjulian/homebrew-core,mvitz/homebrew-core,straxhaber/homebrew-core,wolffaxn/homebrew-core,bigbes/homebrew-core,chrisfinazzo/homebrew-core,jvehent/homebrew-core,zmwangx/homebrew-core,JCount/homebrew-core,git-lfs/homebrew-core,jabenninghoff/homebrew-core,spaam/homebrew-core,wolffaxn/homebrew-core,lasote/homebrew-core,Moisan/homebrew-core,Moisan/homebrew-core,kunickiaj/homebrew-core,kuahyeow/homebrew-core,JCount/homebrew-core,grhawk/homebrew-core,lasote/homebrew-core,maxim-belkin/homebrew-core,grhawk/homebrew-core,ilovezfs/homebrew-core,tkoenig/homebrew-core,nbari/homebrew-core,rwhogg/homebrew-core,zyedidia/homebrew-core,andyjeffries/homebrew-core,aren55555/homebrew-core,passerbyid/homebrew-core,jabenninghoff/homebrew-core,sdorra/homebrew-core,lembacon/homebrew-core,jvillard/homebrew-core,DomT4/homebrew-core,spaam/homebrew-core,lemzwerg/homebrew-core,sjackman/homebrew-core,sjackman/homebrew-core,rwhogg/homebrew-core,moderndeveloperllc/homebrew-core,chrisfinazzo/homebrew-core,j-bennet/homebrew-core,git-lfs/homebrew-core,Homebrew/homebrew-core,smessmer/homebrew-core,zmwangx/homebrew-core,ShivaHuang/homebrew-core,andyjeffries/homebrew-core,makigumo/homebrew-core,mvbattista/homebrew-core,lembacon/homebrew-core,maxim-belkin/homebrew-core,ylluminarious/homebrew-core,mvitz/homebrew-core,adamliter/homebrew-core,aren55555/homebrew-core,cblecker/homebrew-core,ylluminarious/homebrew-core,FinalDes/homebrew-core,mahori/homebrew-core,mbcoguno/homebrew-core,Linuxbrew/homebrew-core,gserra-olx/homebrew-core,mfikes/homebrew-core,jvehent/homebrew-core,jvillard/homebrew-core,filcab/homebrew-core,robohack/homebrew-core,LinuxbrewTestBot/homebrew-core,aabdnn/homebrew-core,FinalDes/homebrew-core,kuahyeow/homebrew-core,mbcoguno/homebrew-core,dsXLII/homebrew-core,robohack/homebrew-core,nandub/homebrew-core,lemzwerg/homebrew-core,edporras/homebrew-core,fvioz/homebrew-core,jdubois/homebrew-core,kunickiaj/homebrew-core,ShivaHuang/homebrew-core,tkoenig/homebrew-core,sdorra/homebrew-core,nbari/homebrew-core,smessmer/homebrew-core,aabdnn/homebrew-core,mvitz/homebrew-core,mbcoguno/homebrew-core,jdubois/homebrew-core,uyjulian/homebrew-core,makigumo/homebrew-core,nandub/homebrew-core,adam-moss/homebrew-core,j-bennet/homebrew-core,straxhaber/homebrew-core,bcg62/homebrew-core,cblecker/homebrew-core,fvioz/homebrew-core,battlemidget/homebrew-core,adam-moss/homebrew-core,stgraber/homebrew-core,adamliter/homebrew-core,forevergenin/homebrew-core,bfontaine/homebrew-core,reelsense/homebrew-core